In Java tryLock(long time, TimeUnit unit) can be used as a non-blocking attempt to acquire the lock. How can the equivalent in python be achieved? (Pythonic | idiomatic way is preferred!)
Java tryLock:
ReentrantLock lock1 = new ReentrantLock() if (lock1.tryLock(13, TimeUnit.SECONDS)) { ... } Python Lock:
import threading lock = Lock() lock.acquire() # how to lock.acquire(timeout = 13) ? The "try lock" behaviour can be obtained using threading module's Lock.acquire(False) (see the Python doc):
import threading import time my_lock = threading.Lock() successfully_acquired = my_lock.acquire(False) if successfully_acquired: try: print "Successfully locked, do something" time.sleep(1) finally: my_lock.release() else: print "already locked, exit" I can't figure out a satisfactory way to use with here.
Ouch, my bad! I should have read the python reference for Locks to begin with!
Lock.acquire([blocking])
When invoked with the blocking argument set to
False, do not block. If a call with blocking set toTruewould block, returnFalseimmediately; otherwise, set the lock to locked and returnTrue.
So I can just do something like this (or something more advanced even :P ):
import threading import time def my_trylock(lock, timeout): count = 0 success = False while count < timeout and not success: success = lock.acquire(False) if success: break count = count + 1 time.sleep(1) # should be a better way to do this return success lock = threading.Lock() my_trylock(lock, 13)